Copper deficiency: A potential model for determining the role of mitochondria in cardiac aging

Copper homeostasis dysregulation in respiratory diseases: a review of current knowledge

Cu is an essential micronutrient for various physiological processes in almost all human cell types. Given the critical role of Cu in a wide range of cellular processes, the local concentrations of Cu and the cellular distribution of Cu transporter proteins in the lung are essential for maintaining a steady-state internal environment. Dysfunctional Cu metabolism or regulatory pathways can lead to an imbalance in Cu homeostasis in the lungs, affecting both acute and chronic pathological processes. Recent studies have identified a new form of Cu-dependent cell death called cuproptosis, which has generated renewed interest in the role of Cu homeostasis in diseases. Cuproptosis differs from other known cell death pathways. This occurs through the direct binding of Cu ions to lipoylated components of the tricarboxylic acid cycle during mitochondrial respiration, leading to the aggregation of lipoylated proteins and the subsequent downregulation of Fe-S cluster proteins, which causes toxic stress to the proteins and ultimately leads to cell death. Here, we discuss the impact of dysregulated Cu homeostasis on the pathogenesis of various respiratory diseases, including asthma, chronic obstructive pulmonary disease, idiopathic interstitial fibrosis, and lung cancer. We also discuss the therapeutic potential of targeting Cu. This study highlights the intricate interplay between copper, cellular processes, and respiratory health. Copper, while essential, must be carefully regulated to maintain the delicate balance between necessity and toxicity in living organisms. This review highlights the need to further investigate the precise mechanisms of copper interactions with infections and immune inflammation in the context of respiratory diseases and explore the potential of therapeutic strategies for copper, cuproptosis, and other related effects.

High Copper Intake Is Associated with Decreased Likelihood of Abdominal Aortic Calcification in Middle-Aged and Older US Adults

The purpose of our study was primarily to investigate the relationship between dietary copper intake and abdominal aortic calcification (AAC) in US adults. We used data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 for our analysis. Multivariate linear regression analysis was used to explore the relationship between copper intake and AAC scores. We also used multivariate logistic regression analysis to explore the association between copper intake and the risk of AAC and severe AAC. We also examined whether there was a nonlinear relationship between copper intake and AAC scores and risk of AAC and severe AAC using restricted cubic splines (RCS) analysis. In addition, we also performed subgroup analysis and interaction tests. A total of 2897 participants were recruited in this study. The mean AAC score of the participants was 1.46 ± 0.11, and the prevalence of AAC and severe AAC among the participants was 28.53% and 7.68%, respectively. In the fully adjusted model, a negative association of copper intake with AAC scores (β =  - 0.16, 95%CI: - 0.49 ~ 0.17) and the risk of AAC (OR = 0.85, 95% CI: 0.61-1.19) and severe AAC (OR = 0.82, 95% CI: 0.49-1.38) was observed. Compared to participants in the lowest tertile of copper intake, participants in the highest tertile of copper intake had a 0.37-unit decrease in mean AAC score (β =  - 0.37, 95% CI: - 0.90-0.15) and a significant 38% and 22% decrease in risk of AAC (OR = 0.62, 95% CI: 0.41-0.95) and severe AAC (OR = 0.78, 95% CI: 0.34 - 1.77), respectively. The results of subgroup analyses and interaction tests suggested no significant differences in AAC scores and AAC risk between the different strata. In contrast, the risk of severe AAC was significantly dependent on the patients' diabetes status. Increased copper intake was associated with decreased AAC scores and decreased likelihood of AAC and severe AAC.

Dietary Copper Deficiency Leads to Changes in Gene Expression Indicating an Increased Demand for NADH in the Prefrontal Cortex of the Rat's Brain

Copper is an essential element to brain cells as it is a cofactor and a structural component of various enzymes involved in energy metabolism pathways. Accumulating evidence points to the pivotal role of copper deficiency in neurodegeneration resulting from impaired copper homeostasis. Despite the indisputable role of copper in mitochondrial respiration, its homeostasis regulation in the brain tissue remains unclear. The assessment of changes in the expression of genes encoding key pathways of energy metabolism can greatly benefit further studies exploring copper’s role in neurodegeneration. Using a rat model, we investigate whether the replacement of the inorganic form of copper with metallic nanoparticles containing copper or complete deprivation of copper from the diet have an impact on the expression of genes involved in energy metabolism in the prefrontal cortex of the rats’ brain. Herein, we indicate that removing inorganic copper from the normal standard diet or the replacement with copper nanoparticles can lead to programmed energy metabolism changes. It can be recognized that some of these changes indicate an increased demand for NADH in the prefrontal cortex of the rat’s brain, probably as a result of adaptation effect.

Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins: Focus on sample preparation and derivatization conditions

Protein oxidation is involved in regulatory physiological events as well as in damage to tissues and is thought to play a key role in the pathophysiology of diseases and in the aging process. Protein-bound carbonyls represent a marker of global protein oxidation, as they are generated by multiple different reactive oxygen species in blood, tissues and cells. Sample preparation and stabilization are key steps in the accurate quantification of oxidation-related products and examination of physiological/pathological processes. This review therefore focuses on the sample preparation processes used in the most relevant methods to detect protein carbonyls after derivatization with 2,4-dinitrophenylhydrazine with an emphasis on measurement in plasma, cells, organ homogenates, isolated proteins and organelles. Sample preparation, derivatization conditions and protein handling are presented for the spectrophotometric and HPLC method as well as for immunoblotting and ELISA. An extensive overview covering these methods in previously published articles is given for researchers who plan to measure protein carbonyls in different samples.